Data: a1, b2, c3 Cardinality: 1 Permutations: {a1, b2}, {a1, c3}, {b2, c3}, Data: a1, b2, c3, d4 Cardinality: 2 Permutations: {{a1, b2}, {c3, d4}} {{a1, c3}, {b2, d4}} {{a1, d4}, {c3, d4}}